login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

a(0) = 0; for n > 0, a(n) = n + a((Sum_{k=0..n-1} a(k)) mod n).
2

%I #27 Dec 19 2019 08:37:20

%S 0,1,3,4,4,8,9,8,16,25,26,19,16,38,39,24,16,18,22,38,59,45,81,61,28,

%T 41,67,66,95,37,69,112,40,71,50,147,183,77,75,120,62,91,119,104,94,

%U 116,55,63,70,196,145,75,92,91,170,110,176,177,241,109

%N a(0) = 0; for n > 0, a(n) = n + a((Sum_{k=0..n-1} a(k)) mod n).

%H Samuel B. Reid, <a href="/A330249/b330249.txt">Table of n, a(n) for n = 0..10000</a>

%e a(1) = 1 + a(0 mod 1) = 1.

%e a(2) = 2 + a((0+1) mod 2) = 3.

%e a(3) = 3 + a((0+1+3) mod 3) = 4.

%e a(4) = 4 + a((0+1+3+4) mod 4) = 4.

%t a[0] = 0; a[n_] := a[n] = n + a[Mod[Sum[a[k], {k, 0, n-1}], n]]; Array[a, 100, 0] (* _Amiram Eldar_, Dec 07 2019 *)

%o (PARI) lista(nn) = {my(v=vector(nn+1), s=0); v[1]=0; for(n=1, nn, v[n+1]=n+v[s%n+1]; s+=v[n+1]); v; } \\ _Jinyuan Wang_, Dec 07 2019

%Y Cf. A330256, A066910.

%K nonn

%O 0,3

%A _Samuel B. Reid_, Dec 06 2019